The naturally occurring retinoic acid isomers 13-cis-retinoic acid and all-trans-retinoic acid (ATRA) influence processes of morphogenesis and differentiation. The effect of retinoic acid is mediated via the retinoic acid receptors α, β and γ (RARα, RARβ, RARγ). In the absence of ligands...
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The phoshatidylinositol-3 kinase (PI3K) can be activated by binding directly or via the protein IRS-1 to the activated receptor tyrosine kinase. Alternatively, PI3K can be activated by binding to the GTP-bound form of the membrane bound protein Ras. Active PI3K catalyzes the formation of...
Onkoview 2010
Effects of proteinases with metalloproteinase domains (MMPs, ADAMs) on tumour progression
By degradation of cell adhesion molecules, metalloproteases increase the motility of epithelial cells. Growth factors, which are bound to the plasma membrane, are released. In this way, the growth factors can reach their receptors on target cells. Growth factors, for example TGF-b, may...
Epithelial cells are in contact with the extracellular matrix. This video shows the acinus of a mammary gland surrounded by connective tissue. Fibroblasts, macrophages and endothelial cells are embedded in the connective tissue. After the malignant transformation of a mammary gland cell...
In normal cells without a Wnt signal a cytosolic destruction complex phosphorylates the signaling protein b-catenin leading to its degradation. In the presence of the extracellular Wnt factor, activation of the membrane bound receptor FZD leads to the dissociation of the destruction...